Java 中文官方教程 2022 版（三十）（2）

String newString(int codePoint) {
    return new String(Character.toChars(codePoint));
}

String newString(int codePoint) {
    if (Character.charCount(codePoint) == 1) {
        return String.valueOf(codePoint);
    } else {
        return new String(Character.toChars(codePoint));
    }
}

String[] newStrings(int[] codePoints) {
    String[] result = new String[codePoints.length];
    char[] codeUnits = new char[2];
    for (int i = 0; i < codePoints.length; i++) {
        int count = Character.toChars(codePoints[i], codeUnits, 0);
        result[i] = new String(codeUnits, 0, count);
    }
    return result;
}

// recommended
System.out.printf("Character %c is invalid.%n", codePoint);

// not recommended
System.out.println("Character " + String.valueOf(char) + " is invalid.");

Locale[] locales = BreakIterator.getAvailableLocales();

BreakIterator characterIterator =
    BreakIterator.getCharacterInstance(currentLocale);

String house = "\u0628" + "\u064e" + "\u064a" + "\u0652" + "\u067a" + "\u064f";

BreakIterator arCharIterator = BreakIterator.getCharacterInstance(
                                   new Locale ("ar","SA"));
listPositions (house, arCharIterator);

static void listPositions(String target, BreakIterator iterator) {
    iterator.setText(target);
    int boundary = iterator.first();
    while (boundary != BreakIterator.DONE) {
        System.out.println (boundary);
        boundary = iterator.next();
    }
}

0
2
4
6

BreakIterator wordIterator =
    BreakIterator.getWordInstance(currentLocale);

Locale currentLocale = new Locale ("en","US");
BreakIterator wordIterator =
    BreakIterator.getWordInstance(currentLocale);
String someText = "She stopped. " +
    "She said, \"Hello there,\" and then went " +
    "on.";
markBoundaries(someText, wordIterator);

static void markBoundaries(String target, BreakIterator iterator) {
    StringBuffer markers = new StringBuffer();
    markers.setLength(target.length() + 1);
    for (int k = 0; k < markers.length(); k++) {
        markers.setCharAt(k,' ');
    }
    iterator.setText(target);
    int boundary = iterator.first();
    while (boundary != BreakIterator.DONE) {
        markers.setCharAt(boundary,'^');
        boundary = iterator.next();
    }
    System.out.println(target);
    System.out.println(markers);
}

She stopped.  She said, "Hello there," and then
^  ^^      ^^ ^  ^^   ^^^^    ^^    ^^^^  ^^   ^
went on.
^   ^^ ^^

static void extractWords(String target, BreakIterator wordIterator) {
    wordIterator.setText(target);
    int start = wordIterator.first();
    int end = wordIterator.next();
    while (end != BreakIterator.DONE) {
        String word = target.substring(start,end);
        if (Character.isLetterOrDigit(word.charAt(0))) {
            System.out.println(word);
        }
        start = end;
        end = wordIterator.next();
    }
}

She
stopped
She
said
Hello
there
and
then
went
on

BreakIterator sentenceIterator =
    BreakIterator.getSentenceInstance(currentLocale);

She stopped.  She said, "Hello there," and then went on.
^             ^                                         ^
He's vanished!  What will we do?  It's up to us.
^               ^                 ^             ^
Please add 1.5 liters to the tank.
^    

BreakIterator lineIterator =
    BreakIterator.getLineInstance(currentLocale);

She stopped.  She said, "Hello there," and then went on.
^   ^         ^   ^     ^      ^     ^ ^   ^    ^    ^  ^

There are twenty-four hours in a day.
^     ^   ^      ^    ^     ^  ^ ^   ^

static void formatLines(
    String target, int maxLength,
    Locale currentLocale) {
    BreakIterator boundary = BreakIterator.
        getLineInstance(currentLocale);
    boundary.setText(target);
    int start = boundary.first();
    int end = boundary.next();
    int lineLength = 0;
    while (end != BreakIterator.DONE) {
        String word = target.substring(start,end);
        lineLength = lineLength + word.length();
        if (lineLength >= maxLength) {
            System.out.println();
            lineLength = word.length();
        }
        System.out.print(word);
        start = end;
        end = boundary.next();
    }
}

String moreText =
    "She said, \"Hello there,\" and then " +
    "went on down the street. When she stopped " +
    "to look at the fur coats in a shop + "
    "window, her dog growled. \"Sorry Jake,\" " +
    "she said. \"I didn't know you would take " +
    "it personally.\"";
formatLines(moreText, 30, currentLocale);

She said, "Hello there," and
then went on down the
street. When she stopped to
look at the fur coats in a
shop window, her dog
growled. "Sorry Jake," she
said. "I didn't know you
would take it personally."

ArabicDigitsPanel(String fontname) {
    HashMap map = new HashMap();
    Font font = new Font(fontname, Font.PLAIN, 60);
    map.put(TextAttribute.FONT, font);
    map.put(TextAttribute.NUMERIC_SHAPING,
        NumericShaper.getShaper(NumericShaper.ARABIC));
    FontRenderContext frc = new FontRenderContext(null, false, false);
    layout = new TextLayout(text, map, frc);
}
// ...
public void paint(Graphics g) {
    Graphics2D g2d = (Graphics2D)g;
    layout.draw(g2d, 10, 50);
}